Some drivers compare struct clk pointers as a means of knowing
if the two pointers reference the same clock hardware. This behavior is
dubious (drivers must not dereference struct clk), but did not cause any
regressions until the per-user struct clk patch was merged. Now the test
for matching clk's will always fail with per-user struct clk's.
clk_is_match is introduced to fix the regression and prevent drivers
from comparing the pointers manually.
Fixes: 035a61c314 ("clk: Make clk API return per-user struct clk instances")
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: const arguments to clk_is_match() and
remove unnecessary ternary operation]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Adds a way for clock consumers to set maximum and minimum rates. This
can be used for thermal drivers to set minimum rates, or by misc.
drivers to set maximum rates to assure a minimum performance level.
Changes the signature of the determine_rate callback by adding the
parameters min_rate and max_rate.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[sboyd@codeaurora.org: set req_rate in __clk_init]
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate
migrated clk-private.h changes to clk.c]
This new function is similar to clk_set_parent(), except that it doesn't
actually change the parent. It merely checks that the given parent clock
can be a parent for the given clock.
A situation where this is useful is to check that a particular setup is
valid before switching to it. One specific use-case for this is atomic
modesetting in the DRM framework where setting a mode is divided into a
check phase where a given configuration is validated before applying
changes to the hardware.
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
fixes and enhancements to existing drivers as well as new drivers. This
tag contains a bit more arch code than I usually take due to some OMAP2+
changes. Additionally it contains the restart notifier handlers which
are merged as a dependency into several trees.
The PXA changes are the only messy part. Due to having a stable tree I
had to revert one patch and follow up with one more fix near the tip of
this tag. Some dead code is introduced but it will soon become live code
after 3.18-rc1 is released as the rest of the PXA family is converted
over to the common clock framework.
Another trend in this tag is that multiple vendors have started to push
the complexity of changing their CPU frequency into the clock driver,
whereas this used to be done in CPUfreq drivers.
Changes to the clk core include a generic gpio-clock type and a
clk_set_phase() function added to the top-level clk.h api. Due to some
confusion on the fbdev mailing list the kernel boot parameters
documentation was updated to further explain the clk_ignore_unused
parameter, which is often required by users of the simplefb driver.
Finally some fixes to the locking around the clock debugfs stuff was
done to prevent deadlocks when interacting with other subsystems.
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Merge tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux
Pull clock tree updates from Mike Turquette:
"The clk tree changes for 3.18 are dominated by clock drivers. Mostly
fixes and enhancements to existing drivers as well as new drivers.
This tag contains a bit more arch code than I usually take due to some
OMAP2+ changes. Additionally it contains the restart notifier
handlers which are merged as a dependency into several trees.
The PXA changes are the only messy part. Due to having a stable tree
I had to revert one patch and follow up with one more fix near the tip
of this tag. Some dead code is introduced but it will soon become
live code after 3.18-rc1 is released as the rest of the PXA family is
converted over to the common clock framework.
Another trend in this tag is that multiple vendors have started to
push the complexity of changing their CPU frequency into the clock
driver, whereas this used to be done in CPUfreq drivers.
Changes to the clk core include a generic gpio-clock type and a
clk_set_phase() function added to the top-level clk.h api. Due to
some confusion on the fbdev mailing list the kernel boot parameters
documentation was updated to further explain the clk_ignore_unused
parameter, which is often required by users of the simplefb driver.
Finally some fixes to the locking around the clock debugfs stuff was
done to prevent deadlocks when interacting with other subsystems."
* tag 'clk-for-linus-3.18' of git://git.linaro.org/people/mike.turquette/linux: (99 commits)
clk: pxa clocks build system fix
Revert "arm: pxa: Transition pxa27x to clk framework"
clk: samsung: register restart handlers for s3c2412 and s3c2443
clk: rockchip: add restart handler
clk: rockchip: rk3288: i2s_frac adds flag to set parent's rate
doc/kernel-parameters.txt: clarify clk_ignore_unused
arm: pxa: Transition pxa27x to clk framework
dts: add devicetree bindings for pxa27x clocks
clk: add pxa27x clock drivers
arm: pxa: add clock pll selection bits
clk: dts: document pxa clock binding
clk: add pxa clocks infrastructure
clk: gpio-gate: Ensure gpiod_ APIs are prototyped
clk: ti: dra7-atl-clock: Mark the device as pm_runtime_irq_safe
clk: ti: LLVMLinux: Move __init outside of type definition
clk: ti: consider the fact that of_clk_get() might return an error
clk: ti: dra7-atl-clock: fix a memory leak
clk: ti: change clock init to use generic of_clk_init
clk: hix5hd2: add I2C clocks
clk: hix5hd2: add watchdog0 clocks
...
A common operation for a clock signal generator is to shift the phase of
that signal. This patch introduces a new function to the clk.h API to
dynamically adjust the phase of a clock signal. Additionally this patch
introduces support for the new function in the common clock framework
via the .set_phase call back in struct clk_ops.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Both the pr_err and the additional kerneldoc aim to help when debugging
errors thrown from within a clock rate-change notifier callback.
Reported-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The clock accuracy is expressed in ppb (parts per billion) and represents
the possible clock drift.
Say you have a clock (e.g. an oscillator) which provides a fixed clock of
20MHz with an accuracy of +- 20Hz. This accuracy expressed in ppb is
20Hz/20MHz = 1000 ppb (or 1 ppm).
Clock users may need the clock accuracy information in order to choose
the best clock (the one with the best accuracy) across several available
clocks.
This patch adds clk accuracy retrieval support for common clk framework by
means of a new function called clk_get_accuracy.
This function returns the given clock accuracy expressed in ppb.
In order to get the clock accuracy, this implementation adds one callback
called recalc_accuracy to the clk_ops structure.
This callback is given the parent clock accuracy (if the clock is not a
root clock) and should recalculate the given clock accuracy.
This callback is optional and may be implemented if the clock is not
a perfect clock (accuracy != 0 ppb).
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.
Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Many drivers are shared between architectures that may or may not have
HAVE_CLK selected for them. To remove compilation errors for them we
enclose clk_*() calls in these drivers within #ifdef CONFIG_HAVE_CLK,
#endif.
This patch removes the need of these CONFIG_HAVE_CLK statements, by
introducing dummy routines when HAVE_CLK is not selected by platforms.
So, definition of these routines will always be available. These calls
will return error for platforms that don't select HAVE_CLK.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Garzik <jgarzik@redhat.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: viresh kumar <viresh.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
framework improvments, platform ports and new DT bindings.
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Merge tag 'clk-for-linus' of git://git.linaro.org/people/mturquette/linux
Pull common clk framework changes from Michael Turquette:
"This includes a small number of core framework improvments, platform
ports and new DT bindings."
Fix up trivial conflicts in drivers/clk/Makefile
* tag 'clk-for-linus' of git://git.linaro.org/people/mturquette/linux: (21 commits)
clk: fix compile for OF && !COMMON_CLK
clk: fix clk_get on of_clk_get_by_name return check
clk: mxs: clk_register_clkdev mx28 usb clocks
clk: add highbank clock support
dt: add clock binding doc to primecell bindings
clk: add DT fixed-clock binding support
clk: add DT clock binding support
ARM: integrator: convert to common clock
clk: add versatile ICST307 driver
ARM: integrator: put symbolic bus names on devices
ARM: u300: convert to common clock
clk: cache parent clocks only for muxes
clk: wm831x: Add initial WM831x clock driver
clk: Constify struct clk_init_data
clk: Add CLK_IS_BASIC flag to identify basic clocks
clk: Add support for rate table based dividers
clk: Add support for power of two type dividers
clk: mxs: imx28: decrease the frequency of ref_io1 for SSP2 and SSP3
clk: mxs: add clkdev lookup for pwm
clk: mxs: Fix the GPMI clock name
...
With commit 766e6a4ec6 (clk: add DT clock binding support),
compiling with OF && !COMMON_CLK is broken.
Reported-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Reported-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The commit 766e6a4 (clk: add DT clock binding support) plugs device
tree clk lookup of_clk_get_by_name into clk_get, and fall on non-DT
lookup clk_get_sys if DT lookup fails.
The return check on of_clk_get_by_name takes (clk != NULL) as a
successful DT lookup. But it's not the case. For any system that
does not define clk lookup in device tree, ERR_PTR(-ENOENT) will be
returned, and consequently, all the client drivers calling clk_get
in their probe functions will fail to probe with error code -ENOENT
returned.
Fix the issue by checking of_clk_get_by_name return with !IS_ERR(clk),
and update of_clk_get and of_clk_get_by_name for !CONFIG_OF build
correspondingly.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Marek Vasut <marex@denx.de>
Tested-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant
Likely, this patch adds support to clk_get to allow drivers to retrieve
clock data from the device tree.
Platforms scan for clocks in DT with of_clk_init and a match table, and
the register a provider through of_clk_add_provider. The provider's
clk_src_get function will be called when a device references the
provider's OF node for a clock reference.
v6 (Rob Herring):
- Return error values instead of NULL to match clock framework
expectations
v5 (Rob Herring):
- Move from drivers/of into common clock subsystem
- Squashed "dt/clock: add a simple provider get function" and
"dt/clock: add function to get parent clock name"
- Rebase to 3.4-rc1
- Drop CONFIG_OF_CLOCK and just use CONFIG_OF
- Add missing EXPORT_SYMBOL to various functions
- s/clock-output-name/clock-output-names/
- Define that fixed-clock binding is a single output
v4 (Rob Herring):
- Rework for common clk subsystem
- Add of_clk_get_parent_name function
v3: - Clarified documentation
v2: - fixed errant ';' causing compile error
- Editorial fixes from Shawn Guo
- merged in adding lookup to clkdev
- changed property names to match established convention. After
working with the binding a bit it really made more sense to follow the
lead of 'reg', 'gpios' and 'interrupts' by making the input simply
'clocks' & 'clock-names' instead of 'clock-input-*', and to only use
clock-output* for the producer nodes. (Sorry Shawn, this will mean
you need to change some code, but it should be trivial)
- Add ability to inherit clocks from parent nodes by using an empty
'clock-ranges' property. Useful for busses. I could use some feedback
on the new property name, 'clock-ranges' doesn't feel right to me.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The comment is inaccurate (it actually ends the CONFIG_COMMON_CLK
section, there's no else) and given that we've just got a single level
of ifdef isn't really needed anyway.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Allow clk API users to simplify their cleanup paths by providing a
managed version of clk_get() and clk_put().
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The common clock framework defines a common struct clk useful across
most platforms as well as an implementation of the clk api that drivers
can use safely for managing clocks.
The net result is consolidation of many different struct clk definitions
and platform-specific clock framework implementations.
This patch introduces the common struct clk, struct clk_ops and an
implementation of the well-known clock api in include/clk/clk.h.
Platforms may define their own hardware-specific clock structure and
their own clock operation callbacks, so long as it wraps an instance of
struct clk_hw.
See Documentation/clk.txt for more details.
This patch is based on the work of Jeremy Kerr, which in turn was based
on the work of Ben Herrenschmidt.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Rob Herring <rob.herring <at> calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
It's for migrating to generic clk framework API.
The helper functions help cases clk_enable/clk_disable is used
in non-atomic context.
For example, Call clk_enable in probe and clk_disable in remove.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
As discussed previously, there's the need on some platforms to run some
parts of clk_enable() in contexts which can schedule. The solution
which was agreed upon was to provide clk_prepare() and clk_unprepare()
to contain this parts, while clk_enable() and clk_disable() perform
the atomic part.
This patch provides a common definition for clk_prepare() and
clk_unprepare() in linux/clk.h, and provides an upgrade path for
existing implementation and drivers: drivers can start using
clk_prepare() and clk_unprepare() once this patch is merged without
having to wait for platform support. Platforms can then start to
provide these additional functions.
Eventually, HAVE_CLK_PREPARE will be removed from the kernel, and
everyone will have to provide these new APIs.
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This can be used for other arm platforms too as discussed
on the linux-arm-kernel list.
Also check the return value with IS_ERR and return PTR_ERR
as suggested by Russell King.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
clk_get and clk_put may not be used from within interrupt context. Change
comment to this function.
Signed-off-by: Alex Raimondi <raimondi@miromico.ch>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/clk.h is betraying its ARM origins.
Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Michael Turquette